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107 Cards in this Set
- Front
- Back
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2 reasons for mitosis (multicellular eukaryotes)
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grow and repair damage
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bacterial method of reproduction
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binary(prokaryotic) fission
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what triggers DNA replication in bacteria?
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growth to adult size
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bacterial cell wall material
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peptidoglycan
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term for the cell splitting in two
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cytokinesis
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time for bacterial cell cycle (avg)
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20 minutes
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meaning of mitosis
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division of the nucleus
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place where bacterial DNA hangs out
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nucleoid
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who came up with the term "mitosis"?
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Flemming
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what does "mitos" mean? from what language?
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Greek for threads
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totally condensed chromatin
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chromosome
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DNA + histone spools (not condensed)
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chromatin
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molecular definition of gene
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a sequence of DNA bases that codes for one and only one polypeptide chain
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trait definition of gene
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a unit of heritable information
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little waistline of chromosome
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centromere
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protein belt that wraps around chromosome
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kinetochore
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when ONE chromosome is in the duplicated state, the 2 parts are called____
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sister chromatids
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relationship between number of chromosomes and complexity of organism
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there's none.
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all eukaryotes have an __ number of chromosomes
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even
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we have __chromosomes, __ come from each parent
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46, 23
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chromosome #7 from mom + chromosome #7 from dad are called
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a homologous pair
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picture of all chromosomes matched up
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karyotype
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how is a karyotype organized
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length of chromosomes, location of centromere, and banding pattern
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chromosomes #1-22 are called
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autosomals
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chromosome #23 is called
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sex chromosome
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XX = ____
XY = ____ |
female
male |
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arm on longer (shorter) side of centromere
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P arm (Q arm)
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a specific location on a gene
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locus
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cell with one set of instructions
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haploid
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cell with two sets of instructions
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diploid
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how many cells in a person?
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200 trillion
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how many genes in a person?
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25000-30000
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90-95% of the time, the cell is in _____
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interphase
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3 phases of interphase
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G1, S, G2
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when does the cell produce new organelles?
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interphase
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when does the cell replicate its genetic material?
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S (synthesis) phase
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6 phases of M (mitotic) phase
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prophase
prometaphase metaphase anaphase telophase cytokinesis |
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the structure made of microtubules that helps in mitosis
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mitotic spindle
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where the assembly of the spindle begins
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centrosome (animals only!)
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another name for centrosome
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microtubule-organizing center
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a centrosome is made of 2 ___ at a right angle to each other.
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centrioles
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during which phases do the centrosomes move apart?
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prophase and prometaphase
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radial array of short microtubules connected to centrosomes
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aster
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3 things included in the mitotic spindle
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microtubules, centrosomes, asters
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there is one kinetochore for each ___
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sister chromatid
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human haploid number
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23
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how does the zygote go from macroscopic to microscopic?
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during cleavage, the G1 phase is really short. this lets the cell keep splitting without growing larger in between.
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unregulated mitosis causes___
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cancer
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where are the 3 checkpoints/restriction points?
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G1, G2, M
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during which phase do the cells double in size?
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G1
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when are the organelles duplicated?
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G1
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what does the G1 checkpoint check for? (3)
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conditions right for mitosis?
large enough cell? enough cyclins? |
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what's G0
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a long term adult stage where the cell isn't preparing for mitosis
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what can cause a cell to go from G0 --> G1?
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injury
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what happens during the S phase?
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DNA replication. by the end of S, chromosomes are in the duplicated state with sister chromatids attached at the centromere
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when is the centriole pair replicated?
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G2
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what protein is used to make microtubules?
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tubulin
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when are the enzymes needed for mitosis made?
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G2
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when do the chromosomes begin condensing?
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prophase
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when does the nucleolus go away?
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prophase
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what do the centrosomes do during prophase?
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start moving apart
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what do aster fibers do?
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help distribute pressure so the cell doesn't burst
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when's the best time to view chromosomes? why?
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prometaphase, they're most condensed here
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what happens to the nuclear membrane during prometaphase?
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it breaks down and becomes part of the ER
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microtubules that attach to kinetochores
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kinetochore microtubules
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what's the longer of the 2 long microtubules?
what do they interact with? |
non-kinetochore microtubules
w/those coming from the other centrosome |
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when are the centrosomes at complete opposite ends of the cell?
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metaphase
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during metaphase, the kinetochore microtubules pull the chromosomes to the ____/____
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metaphase plate/spindle equator
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what is checked at the M (metaphase of M-phase) checkpoint?
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that each kinetochore has a microtubule attached to it
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what main thing happens in anaphase?
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kinetochore microtubules pull the sister chromatids apart
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after they're pulled apart in anaphase, how many chromosomes are present in the cell? (humans)
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92
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what do the non-kinetochore microtubules do during anaphase
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stretch the cell into an egg shape by pushing against each other
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what does "telo" mean
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end
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when does the spindle break apart?
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telophase
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what do the chromosomes do in telophase? what 2 things come back?
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uncondense/relax
nucleolus appears and nuclear membrane forms |
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what happens while telophase is finishing?
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cytokinesis
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when the animal cell is constricted at the equator, the wrinkle is called____
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cleavage furrow
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what do plant cells do during cytokinesis
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cell plate formation
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design of centrioles
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9+0 motif
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material of nuclear membrane
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double phospholipid bilayer
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during what phase do kinetochores appear? disappear?
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synthesis, anaphase
(only present when there are sister chromatids) |
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cyclin concentration ____.
CDK concentration ___. |
fluctuates
is constant |
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CDKs depend on ___ in order to work
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cyclins
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cyclin + CDK =
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MPF (M-phase promoting factor)
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2 treatments for cancer
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radiation and chemotherapy
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whose cells have been dividing since 1951?
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Henrietta Lacks (HeLa cells)
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what controls the cell cycle?
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specific signaling molecules
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what do kinases do?
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phosphorylate proteins to activate/inactivate them
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fraction of people affected by cancer
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1/3
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cause of cancer
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DNA damage. can run in family or be random
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what makes skeletal muscle cells different from all others?
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they do mitosis without cytokinesis
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Experiment:
fuse S + G1 --> ? fuse M + G1 --> ? |
S + S
M + M |
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where are cyclins made?
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ribosomes
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loop where more causes more causes more causes more.....
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positive feedback
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what do activated/phosphorylated MPFs do?
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cause cyclin production to cut down
increase proteases that eat the MPF |
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when cells stop dividing because the space is filled
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density-dependent inhibition
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cells need something to grow on
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anchorage dependence
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when cancer cells break away and spread to other parts of the body
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metastasis
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what stimulates cyclin production?
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growth factors
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name 4 growth factors
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PDGF- platelet derived
EGF-epidermal IGF-insulin-like NGF-nerve |
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genes activated by growth factors
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protooncogenes
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mutated genes that cause cancer
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oncogenes
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name 5 protooncogenes
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ras, mol, myc, fos, jun
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name 6 tumor-supressor genes
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TNF, NF, Rb, p53, BRCA1, BRCA2
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Rb gene stops mutations that can cause ____
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retinoblastoma
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what does p53 do
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stops a damaged-DNA cell in G1 and waits until DNA can be fixed. if it can't, p53 triggers apoptosis
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# codons and hotspots on p53
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393, 4
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